Rotary flying shear mechanism



* Sept 28, 1954 N. P. BEDSON 2,690,220

ROTARY FLYING SHEAR MECHANISM Filed Aug. 2, 1950 ZZ ZZ Z015 lZ l J5 BJ ,Y ,7 W 4 58 l INVENTOR NOEL P. BEDSON DECEASED, ELSIE BEDSON, XECUTRIX Patented Sept. 28 1954 ROTARY FLYING -SHEAR MECHNISM Noel Phillips Bedson, deceased, late of Southport, England, by Elsie Bedson, executrix, Southport,

, England, assignor, by mesne assignments, to Blaw-Knox Company, Pittsburgh, Pa., a corporation of Delaware Application August 2, 1950, 'Serial No. 177,222

1 Claim. 1

This invention relates to novel rotating knives and the effect thereof when used in a rotary flying shear unit. More particularly, it relates to the provision of such knives having parting edges intermediate the faces thereofto part the metal stock without completely cutting through it and propel the forward parted portion to the desired collecting point.

Conventional, rotary ilying shear units used, for example, in rod rolling mills or the like, employ circular knives positioned on opposite sides of the shearing plane in which the pass line is swung when a cut is to be made. These knives are mounted on shafts or spindles which may be placed at an angle of about 30 to the direction of travel of a rod or the like along the pass line. Further, the knives rotate in opposite directions so as toy draw the metal stock into the bite or nip of the knives and effect a complete shearing thereof in a fraction of a second while the rod continues to move. The knives used in such shear mechanism are usually circular discs having substantially planar front and back faces and a conical edge. The knives are so mounted on the shafts that the respective faces of larger diameter substantially lie in the same plane with the circumferential corner element around the base of the conical edge either alongside one another or the axes of the knives are moved closer so that such elements slightly overlap across the shearing plane. Such knives in rotary flying shear units are illustrated in United States Patents Nos. 1,513,070 and 2,170,255.

In the present invention, a new kind of shearing knife is provided in which a circumferential parting edge is provided intermediate the front and rear faces of the knives. Moreover, these knives are separated at all times and avoid the necessity of cutting completely through the metal stock to bey sheared or cut. Still further, the new knives project the parted portion of the metal stock on their f ar side along the pass line with considerable velocity.

Other objects and advantages of this invention will be apparent from the following description and from the drawings which are illustrative only, in which Figure 1 is a view taken along the shearing plane of conventional knives in a standard rotary flying shear unit;

Figure 2 is a partial view of the construction shown in Figure 1 looking at the said knives in the direction the axes thereof extend;

Figure 3 is a View of a, preferred embodiment of this invention taken valong a shearing plane and edgewise to the new knives;

Figure4 is a view of the embodiment shown in Figure 3 taken along the shear plane in the direction the axes of said knives extend;

Figure '5 is a view of the embodiment shown in Figures 3 and 4 taken at right angles to both thereof;

Figure 6 is an enlarged diagrammatic View of a parting of metal stock effected by the embodiment shown in Figures 3 to 5;

Figure 7 is a view of a modified embodiment of this invention taken along the shearing plane and edgewise to the new knives; and

Figure 8 is an enlarged diagrammatic view of a parting of metal stock about to be effected by the modified embodiment shown in Figure 7.

Conventional knives I0 for a standard rotary flying shears unit are illustrated in Figures 1 and 2. Each knife is coaxially mounted on a shaft or spindle Il to which it is secured by a nut I2. Spacing washers I3 may also be used to assist in positioning the knife which is suitably keyed to its respective shaft II. Each knife I0 comprises a near or front face I4 and a far or rear face I5 relative to a pass line I6 for a rod or the like lying within a shearing plane Il normal to a plane containing the axes of the respective parallel shafts Il. A switch pipe I8 is adapted by conventional means as is well understood in the art to swing in shear plane I1 through the tangency sector of the respective knives IU which forms the nip or bite thereof. The direction of rotation of the knives to draw the metal stock to be sheared into the bite I9 may be as illustrated in Figure 2.

Because pass line I6 usually forms an acute angle with the plane defined by and containing the axes of the shafts II, a rod or the like moving along pass line I6 will be completely sheared by the knives I0 while the rod continues to move, the cut portion on the far side of the knives passing along a continuation of the pass line on the approach side 20 of the bite I9 and the remainder of the rod passing along a continuation of the pass line on the delivery side 2l of the bite I9.

Such conventional knives I0 are usually provided with a conical edge 22 tapering in each case outwardly from the face away from the other knife to a plane defined by the far face I5 of knife I0 on the right-hand side of Figure 1 and by the near face i4 of the knife IIJ on the lefthandv side of Figure 1. These faces being the ones respectively of larger diameter remain tangent to each other on shearing plane I'I as the circumferential base corner element 23 of each conical edge 22 is revolved. Sometimes the base corner-elements 23', instead of being tangent to each other on shearing planes l1, overlap along the plane generally defined by the respective faces of larger diameter of the respective knives lo. In this last-mentioned situation, the axes of the shafts Il are closer than the sum of the respective radii of. the said larger faces of the respective knives.

In such prior practice the metal stock moving along the pass line is completely out or sheared by the passage therethrough of the knives which are provided with minimum clearance between them. Moreover, the sheared portion of the metaly stock on the far side of the knives may lose substantially all of the forward component of motion which it had and thereby may fail to reach its desired station or collecting point along the continuation of the pass line.

In a preferred embodiment of this inventio shown in Figures 3 to 5, a new kind of knife 24 is employed in pairs mounted in conventional manner, usually on parallel shafts or spindles k25. These knives are circular discs having front or near faces 26 and rear or far faces 21. Intermediate such faces a circumferential parting edge 28 is provided generally lying in a plane normal to the axis of the respective shaft on which the knife 24 is mounted. A bezel 29 slopes inwardly from each parting edge 28 on each side thereof to the respective faces of the knife. Thus, each parting edge 28 with its bezels forms a double bevel edge, the included acute angle between the sides of which bevel edge may be about 60.

As schematically shown in Figure 3, a housing 32 supports the respective barrels 3i and bearings 32 for each shaft 25. A motor 33 is adjustably mounted on a plate pivotally fastened to the side of housing adjacent each shaft 25. The shaft of each motor 33 is provided with a drive pulley 34 which, by means of belts 35, drives a driven pulley 35 keyed to the rearmost end of each shaft 25.

A pass line 31 for rods or the like passes through a switch pipe 38 which normally is positioned in the approach cusp 39 of the knives 24. In that position, the pass line 31 is continued by the pass line 42 on the far or back side of the knives 24. When, however, switch pipe 38 is swung in parting plane 4l to the position as shown in Figure 5 in dot-and-dash outline, to force the pass line to the other side of the line joining the centers of the respective knives, the pass line 31 is then continued by pass line 42 extending through the delivery cusp 43 of the knives 24. For each of the continuation pass lines and 42, fixed guide pipes 44 and 45 respectively are provided with suitable bell mouths to catch the ends of the respective portions of the rod or the like as they appear on the far side of the knives in a manner well understood in the art.

In this invention, as illustrated in Figures 3 to 6, the parting edges 28 of the pair of knives 24 lie in a single plane, the axes of those knives being separated by a distance greater than the sum of the respective radii thereof. At the same time, at the point litwhere the knives most nearly approach each other, the distance between the parting edges 28 is less than the dimension of the metal stock to be cut measured in the same direction as a line connecting the respective centers of those knives. As seen in Figs. 3 and 6, the distance between the cutting edges of the knives is less than the radius of said rod.

The effect of the use of such an embodiment may be illustrated by reference to Figure 6. In that figure, it may beassumed thatarod 41. is,

i 24 will tend to force rod 41 through point 4t.

passing along rod line 31. At the precise place where the rod is to be parted, switch pipe 38 is swung so as to move the pass line from zone 39 to zone 43 through the point 46. As soon as rod 41 touches the parting edges 28, due to their direction of rotation as shown in the figures, the knives in so doing, the double bevel edges will cut in the rod two aligned V-shaped grooves, or, an annular groove if the rod rotates, having the sides te. In thecourse of this cutting, the sloping sides 29 of the knives will create a wedging action against the sides 48 putting the rod 41 under tension over the reduced or necked portion 50 thereof at the baseof the cut. Such wedging and tension will become sumcient in the course of the cutting by the knives 24 tocomplete the severance of the respective portions 49 and 5I across the neck portion 50.

At the same time, the forward portion 49 of the rod 41 on the far side of the knives 2li will be projected or propelled forwardly along pass line :te with considerable force. Thus, portion 49 is niaterially assisted in reaching its desired station for further movement or collection. The purely diagrammatic illustration in Figure 6 shows portion 49 after the tension has become such as to break the neck or reduced section across the base of the groove defined by the sloping sides 4S in the rod 41'.

Further, the peripheral speed of the parting edges 28 will be usually greatly in excess of components of movement of rods or the like along the pass line on the near side of the knives 2s. The axes. of the shafts 25 may lie in a plane forming an acute angle of 30, for example, with the pass line 31 before the swinging cf switch pipe ES into the dot-anddash position shown in Figure 5. Therefore, such rods as rod 41 or the like are effectively partially cut and the parting completed by breaking, while continuing their forward travel without any retardation of the motion of the rod or portions thereof.

Moreover, inasmuch as the parting edges 2B of the knives 24 are never closer than, for example, one thirty-second of an inch at point d5, no alignment or wear problem can arise with likelihood of the rubbing or wearing against one another. Further, the precise alignment of the respective parting edges 28' within a single plane is not critical in the parting of rods in accordance with this inn vention. These apices or parting edges 28 in practice in accordance with the embodiment illus- `trated in Figures 3 to 5, will not be located a distance aparty greater than that suflicient to com plete the parting by the wedging action of the respective bezels 23.

In a modified embodiment of this invention shown in Figures 7 and 8, a pair of double bevel edge knives 52 are employed and are conventionallymounted on shafts 53 similar to shafts 25. A vpass line 54 passes through a switch pipe 55 similar in construction and operation to switch pipe 39. However, in this modified embodiment, the knives are offset or separated longitudinally in an axial direction. rIhe amount of longitudinal offset is usually less than onehalf the distance between the respective faces of either knife 52. In addition, the distance between the bezel 58 on the far side of the upper knife 52 in Figure 7 and the bezel 59 on the near sde'of thelower knife 52m Figure 7 is less than the diameter `or dimension of the metal stock .tobe parted measured in the direction of the In operation, as diagrammatically shown in Figure 8, this modified embodiment produces a partial cutting of a rod 60 or the like by each of the parting edges 56 which cutting will be in the form of conical annular grooves if there is substantial rotation of the rod during cutting. Otherwise, the respective parting edges 56 and bezels on each side thereof, will produce the respective V-shaped grooves 6I and 62. These grooves Will be connected by a reduced section 63 as the rod 60 passes through the plane containing the axes of the knives 52 and their shafts 53. Again, the respective bezels connecting the parting edges 56 with the front and back faces of the knives 52 exert a Wedging action which in the course of the swing of switch pipe 55 in the shearing plane 5'! from the approach to the delivery side of the knives will put section 63 under such tensile stress as to break it and project the foremost portion 64 along the continuation of the pass line 56 on the approach side of the knives 52.

Although the foregoing embodiments of this invention are described in connection with a rotary flying shears unit in Which the knife shafts are parallel and the distance between such shafts n xed, this invention may also be used with those rotary flying shear mechanisms in Which the respective shafts are provided with eccentric move'- ments relative to each other. Further, this invention will normally be used with shear mechanisms in which the shafts for rotating the parting knives are parallel. However, in some cases, such shafts may be set at an angle to 4each other without material detriment to the results which can be obtained by the practice of this invention. Still further, although the parting knives shown in Figures 3 to 8 are provided with symmetrical parting edges and bezels, the parting edge on such knives may in some cases be located closer to one face than to the other. Other modifications may also be made which are within the spirit of this invention as defined by the scope of the following claim.

What is claimed is:

In combination, in a rod rolling mill having a pass line along Which a rod moves, a rotary ying shear unit comprising a pair of rotatable shafts, a frame in which said shafts are mounted, disc knives mounted -on said shafts, the axes of said knives being substantially stationary While said knives engage and part a rod passing along said pass line, a line joining the centers of said knives being adjacent said pass line, means for laterally moving a rod passing along said pass line to the other side of said line joining said centers to part said rod, each of said knives having a circumferential parting edge and being beveled radially inwardly on each side of said edge to form a generally symmetrical ra dial acute included angle taper to said edge which acute included angle may be about the respective parting edges being generally in alignment and having an oblique position relative to said pass line, said parting edges being separated by a distance during said parting of said rod less than the radius of said rod, and means for rotating said knives in opposite directions at least during said engagement and parting at a linear speed greater than the linear speed of a rod passing along said rod line, the direction of movement of said knives adjacent the plane of movement of the pass line having a velocity component in the direction of movement of a rod along said pass line.

References Cited in the file 0f this patent UNITED STATES PATENTS Number Name Date 897,142 Preston Aug. 25, 1908 1,366,063 Culhane Jan. 18, 1921 1,513,070 Rendleman Oct. 28, 1924 2,170,255 Shepherdson Aug. 22, 1939 FOREIGN PATENTS Number Country Date 446 Italy Aug. 26, 1875 518,628 Germany Aug. 2, 1931 425,900 Great Britain Mar. 15, 1935 .9,267 Great Britain May 19, 1900 

